A lot of VS Lots of

A lot of and lots of are used to express that there is a large quantity of something.
We use a lot of in positive sentences, negative sentences and questions. This expression can be used with countable or uncountable nouns.

Examples:
– There are a lot of dogs in their house. (Countable noun)
– I have a lot of time to answer your questions. (Uncountable noun)
– I saw a lot of people waiting in the queue. (Countable noun)
– We did have a lot of fun, didn’t we? (Uncountable noun)

Note: We use “lots of” in positive and negative sentences, however it is more informal. It can be used with countable or uncountable nouns, and occasionally in questions.